Flotation machine



NMA. I, A H, GARRETT 2,?.7922

FLOTA'PION MACHINE Filed Feb. l5, 1938 4 Sheets-Sheet l HHN "www "Im' 'Hull ruw" Il"y IHIIII "du wrrflu' H Hl'- flllllllll im 1H ff:

` INVENTOR.

Nov, M, i939. A. H. GARRETT 2,79,622 l' FLOTATION MACHINE Filed Feb. 15, 1938 4 Sheets-Sheet 2 Ill! Milian,

Ww Q esq IN VENTOR.

ALI/A GAR/P577 l M ATTORNEY.

Nov. 14, 1939. A. H. GARRETT ZimZZ FLOTATION MACHINE Filed Feb. 15, 1938 4 Sheets-Sheet 3 twill" Nil MHK@ TTORNEY.

Nov. 14, 1939. A. H. GARRETT 2,179,622

FLOTATI 0N MACHINE --Zv INVENTORn BY ALVA A( GA/Wfr ATTORNEY.

Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE FLOTATION MACHINE Alva H. Garrett, Denver, Colo., assigner of iifty per cent to Charles 0. Parker, Denver, Colo.

Application February 15, 1938, Serial No. 190,594

9 Claims. (Cl. 261-93) 'I'his invention relates to a notation machine The impeller I3 is carried on the lower exand has for its principal object the provision of a tremity of a vertical drive shaft I4 which extends highly eicient device oi. this character which will downward through the bowl II. The shaft I4 is have a maximum capacity in proportion to its mounted in an upper bearing I5 and a lower 5 size; in which the impeller shaft will be supbearing I6 both of which are mounted in a sta- 5 ported in two widely spaced-apart bearings, one tionary bearing tube Il which is secured to and of which will be adjacent the impeller, so that a suspended from suitable cross beams I8 posirelatively small shaft and a comparatively high tioned transversely of the frame work lo. speed may be used; and in which the bearing Water from the cell is prevented from enterlo adjacent the impeller will be completely proing the bearing tube Il by means of a cylindrical 10 tected from sand and solution even though it be cup member I9 which is secured to and sealed to located well below the solution level in the mathe Shaft I4 below the loWer bearing l5 and chine. which extends upwardly about the tube Il to a Other objects of the invention are to provide Point obov'e the Solution line in t'he cell. 'I'he a, bottom feed type of cell of large capacity, in cup member I9 rotates as a unit with the shaft 15 which the impeller will rotate in a clear zone free I4 and is preferably entirely supported therebyfrom sand: and to provide a machine in which An air jacket Surrounds the 011D member an exceedingly intimate and eiilcient mixture oi I9 and extends from e point above the solution air and pulp is obtained; and in which a very line, downwardly into the bowl il. The air 20 rapid and continuous flow through each cell is jacket is preferably tapered and sets by gravity 20 possible without decreasing the notation eiliin supporting bracket ring 2|. The air Jacket ciency is reduced in size below the cup member I9 and Other objects and advantages reside in the iS open at its bottom immediately aboVe the imdetail construction of the invention, which is Deller |3- designed for simplicity, economy, and emciency. The bottom of the impeller housing l2 is enged 25 These will becom.more apparent from the folinwardly 8S Shown at 22 to e Central opening 23 lowing description. immediately below the impeller I3.

In the following detailed description of the in- The impeller i3 oonSiStS of o conical outer vention reference is had to the accompanying Sleeve o1' rim Which iS Supported relatively CloSo drawings which form a part hereof, Like m1- to, and in parallel relation with, the inner wall 30 morals refer to like parts in 9,11 views of the oi. the impeller housing I2. It does not contact drawings and throughout the description. the letter, however. The rim is supported from In the drawings: a cup-like hub member 24 by means of radial Fig. 1 is a side elevation of a series of cells in Varies 25 Which extend the full length of the rim.

which the invention is embodied. This view par- The hub member 24 extends upwardly above the 35 tially is broken away to show the interior con- Iim and. When in place in the machine. extends struction, Within the reduced. lower extremity of the air Fig, 2 is a plan view thereof, jacket 20. 'Ihe hub member is formed with air Fig, 3 ls a longitudinal section taken on. the ports 2B in its side wall and with ports 2l in its une 3 3, Fig. 2. bottom. 40

Fig, 4 is a detail plan view of the impeller em- The pulp and solution to be treated is fed into ployed in this invention. the impeller housing by means of a bottom feed Fig. 5 is a cross-section through the impeller Pipe 23 Which extends throughout the entire taken on the line 55, Fig, 4, series of cells between the impeller housings.

Fig. 6 is a detail cross section through one of The boWl il terminates at its top in e Ieo- 45 the cells taken on the line 6 8, Fig. 2. tangular box portion 29, the floor of which is in- The machine consists of a series of aligned dicated at 30. The bowl passes and is sealed cells, each cell being the duplicate oi' the adjato the door 30. At each side of the box portion cent cells, all being supported upon any suitable 29 is a deectlng plate 3| extending the full framework such as indicated at I0. Each cell length 0f the cell. The plates 3| outline the 50 consists of a lower cylindrical bowl II terminatupper portion of the cell and the bowl II forms ing at its bottom in ari axially positioned, dethe lower portion thereof. pressed impeller housing I2. The impeller hous- 'Ihe sides of the box portion 29 extend downing is preferably inverted cone-shaped and enwardly at each side of the deectlng plates 3l.

closes a similarly shaped impeller I3; and terminate above the floor 3o, the interven- 55 ing space being filled with baiile'grid 32 at each side of the cell. The top of the box portion 29 is closed by means of a cover 33, through which the air jacket 2U extends and is sealed by means of suitable packing 34. Thus, a compression zone 35. is formed at the top of each cell by the completely enclosed box portion.

Along each side of each cell below the grids 32 is a pulp launder 36 and along each pulp launder is a froth launder 31.

It is desired to call attention to the fact that the entire impeller assembly and air jacket can be lifted from the cell without discharging the contents thereof, by simply lifting the cross members I8 from the frame work. The assembly can also be raised or lowered to adjust the clearance of the impeller by simply raising the cross members I8 or the bearing 'tube I1 by means of suitable spacing shims or other means. The air jacket can also be raised or lowered by adjusting the wedge-shaped sealing jacket 34 in the cover 33 to obtain the proper clearance between the bottom of the jacket and the impeller. Should additional air be desirable in the cells, this may be obtained from a compressed air line 49 which communicates with each impeller housing through an air inlet nipple 50 controlled by means of an air valve 5I. This air enters the housing in the narrow evacuatedspace around the impeller and discharges directly into the bowl of the cell in a thin conical sheet which interferes in no way with the vacuum of the impeller.

The iiow along the feed pipe 28 is controlled by 'means of suitable gate valves 46. These valves are -normally closed during operation of the machine and are only used for cutting out a certain cell of the series for repairs, etc., by by-passing the pulp from the preceding cell to the succeeding cell through the impeller housing of the intervening cell, or for washing out the entire battery of cells. l

'I'he shafts I4 may be driven in any desired manner. It is preferred however, to mount individual drive motors on each set of the cross members I8 connected directly to flanges 52 on the shafts. Thisallows the motor to be lifted as a part of the impeller assembly when removing or adjusting the latter.

Operation The pulp is fed into the rst cell of the series through the feed pipe 28. The impellersin all cells are rotating in the housing I2y due to the centrifugal action of the impeller which draws the pulp upwardly through the central opening 23 into the hollow impeller from thence it is dis'- charged upwardly and outwardly into the bowl. This upward and outward centrifugal' action completely evacuates the space between the mpeller and the impeller housing wall so that there is nol friction or wear at this point.-

The outgoing. pulp creates a partial vacuum immediately below the hub portion 24 of the impeller which draws in additional pulp and also creates a partial vacuum below the air jacket 20 which draws air downwardly in this jacket and through the open bottom thereof. The larger portion of this air enters the hollow hub of this air jacket through the ports 26. Another portion passes downwardly through the ports 21 into the rapidly moving pulp. Still another portion is drawn outwardly between the hub 24 and the open bottom of the jacket.

This causes a very intimate emulsiiication or intermixing of the air and pulp and creates a pulp pressure within the bowl which forces the pulp upwardly between the plates 3I and against the top of the cell 33 from whence it falls downwardly through the grills 32 into the pulp launders 36.

The solution level in the launders is maintained substantially at the over-flow lip to the froth launders 31 by means of a suitable dischargevalves to be later described. 'I'he froth iiows across the surface of the pulp in the pulp launders into the froth launders 31. The bottoms of the pulp launders are inclined downwardly toward the discharge end of the cells, as shown in Fig. 1, and the pulp ows down this incline to the lowermost point at each side from whence it flows into inwardly extending pulp passages 39 to a pulp chamber 40. From the chamber 40 the pulp iiows beneath a fioor 4I, of a feed chamber 42, thence upwardly to the latter. The iiow from the pulp chamber into the feed chamber 42 is controlled by means of an adjustable plug valve, which will be herein designated the discharge valve 43. From the feed chamber 42 the pulp ows through a feed valve 44 to the feed pipe 28 of the 'next cell.

Each pulp chamber 40 is provided with a bypass valve 45 which can be used to allow a portion of the pulp to by-pass to the feed pipe 28 thence back to the impeller housing of the lcell from which it has just been discharged.

Each cell carries its own feed chamber 42 and a discharge chamber 40 which project from that cell into a receiving depression in the adjacent cell so that the entire series of cells interlock one with another. 'I'he chambers 40 and 42 are separated by means of an adjustable height partition 41, over which the pulp may flow in case of surges or valve stoppages into the feed chamber 42 of the next cell. Ordinarily, however, the discharge valves 40 are so adjusted as to maintain the proper solution height in each cell so that there is no overiiowing at this point.

The valves 43, 44, and 45, are controlled from the top of the cell by means of suitable valve handles 43', 44', and 45', respectively. 'Ihe air can enter the jacket 20 through the open top thereof there being air holes 48 to facilitate its entrance. The cells may be drained by means of suitable drain cocks 53.

The bearing tube I1 and the interior of the cup member I9 are always free from pulp and solution. The intervening space between the cup member I9 and the air jacket 20 is immediately evacuated by the impeller so that the cup memtlcer I9 rotates freely in air without solution fricion.

It will be noted that this invention produces a light-weight, fast-moving machine which greatly reduces transportation and installation costs. It passes a small volume of 'pulpcontinuously at a rapid rate thereby greatly reducing the time element over the slow-motion, large-volume machines. This results in a low power and maintenance cost and in view of the fact that the entire impeller assembly can be quickly and easily removed, there is a minimum loss of time for repairs or replacements.

'I'he machine incorporates: a gravity flow feed; delivery of the pulp to a quiet froth zone which receives all of the pulp ow; a positive control of pulp level; and returns a volume of pulp to the agitating chamber which gives a polsitive control of the gravity ow from cell to ce l.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. In a flotation cell, means for supporting an impeller adjacent the bottom of said cell, comprising: a vertical shaft extending downwardly within said cell to said impeller; a shaft support extending downwardly adjacent said shaft; means supporting said shaft at its upper extremity; bearings carried by said shaft support and supporting said shaft in said cell, the lowermost bearing being positioned adjacent said impeller; and a tubular cup member sealed to said shaft below said lower-most bearing and extending upwardly concentrically thereabout to enclose said shaft support and to prevent said solution from reaching said bearings.

2. In a flotation cell, means for supporting an impeller adjacent the bottom of said cell, comprising: a vertical shaft extending downwardly within said cell to said impeller; a shaft support extending downwardly adjacent said shaft; means supporting said shaft at its upper extremity; bearings carried by said shaft support and supporting said shaft in said cell, theY lowerinost bearing being positioned adjacent said impeller; a tubular cup member sealed to said shaft below said lowermost bearing and extending upwardly concentrically thereabout to enclose said shaft support and to prevent said solution from reaching said bearings; and said cup member being affixed to and rotating with said shaft.

3. In a flotation cell, means for supporting an impeller adjacent the bottom of said cell, comprising: a vertical shaft extending downwardly adjacent said shaft; means supporting said shaft at its upper extremity; bearings carried by said shaft support and supporting said shaft in said cell, the lower-most bearing being positiond adjacent said impeller; a tubular cup member sealed to said shaft below said lower-most bearlng and extending upwardly concentrically thereabout to enclose said shaft support and to prevent said solution from reaching said bearings; said cup member being affixed to and rotating with said shaft; and a stationary air sleeve surrounding said cup member; said air sleeve being open at its bottom to allow air to be drawn therethrough into said impeller.

4. 0n a flotation machine, an agtating chamber; a supporting member above said chamber; an impeller housing depressed into the bottom of said chamber; a bearing tube suspended from said supporting member over said housing; shaft bearings in said tube; a shaft extending downwardly through said bearings and terminating Within said housing; an impeller carried by said shaft within said housing; and a tubular protecting member secured and sealed to said shaft below said bearing tube and extending upwardly about said bearing tube to a point above the solution line in said chamber.

5. 0n a flotation machine, an agitating chamber; a supporting member above said chamber; an impeller housing depressed into the bottom of said chamber; a bearing tube suspended from said supporting member over said housing; shaft bearings in said tube; a shaft extending downwardly through said bearings and terminating within said housing; an impeller carried by said shaft within said housing; a. tubular protecting member `secured and sealed to said shaft below said bearing tube and extending upwardlyabout said bearing tube to a point above the solution line in said chamber; and an air jacket extending downwardly about said tubular protecting member and .opening to said impeller below said protecting member.

6. On a flotation machine, an agitating chamber; a supporting member above said chamber; an impeller housing depressed into the bottom of said chamber; a bearing tube suspended from said supporting member over said housing; shaft bearings in said tube; a shaft extending downwardly through said bearings and terminating within said housing; an impeller carried by said shaft within said housing; a tubular protecting member secured and sealed to said shaft below said bearing tube and extending upwardly about said bearing tube to a point above the solution line in said chamber; and an air jacket extending downwardly about said tubular protecting member; said jacket being reduced in diameter at its bottom and extending within said impeller i housing to define an annular outlet for the latter.

7. An impeller for otation machines com- I prising: an annular rim band open at both its top and bottom; a cup-shaped member concentric within said rim band and forming a hub therefor; radical, axially extending vanes supporting said rim band from said cup-shaped member, said latter member being perforated to allow air to pass from said cup-shaped member into the spaces between said vanes; and means for securing a drive shaft at the middle of the bottom of said cup-shaped member.

8. An impeller for flotation machines comprising: an annular rim band open at both its top and bottom; a cup-shaped member concentric within said rim band and forming a hub therefor; radical, axially extending vanes supporting said rim band from said cup-shaped member, said latter member being perforated to allow air to pass from said cup-shaped member into the spaces between said vanes; and means for securing a drive shaft at the middle of the bottom of said cup-shaped member, said rim band having a greater diameter at its top than at its bottom; a similarly shaped impeller housingsurrounding said rim band in close proximity thereto, said housing being completely open at its top; a bottom in said housing; and a pulp conduit in said housing below said bottom, their being an axially positioned passage from said conduit through the bottom of said housing.

9. An impeller for notation machines comprising: a conical-shaped annular rim band open at both its top and bottom; a cup-shaped member concentric with said rim band and forming a hub therefor; radial, axially extending vanes supporting said rim band from said cup-shaped member; means for securing a drive shaft at the center of the bottom oi' said cup-shaped member a similarly shaped impeller housing surrounding said rim band in close proximity thereto; a bottom in said housing; and a pulp conduit in said housing below said bottom, there being an axially positioned passage from said conduit through the bottom of said housing, and perforations in the bottom of said cup-shaped hub member to allow air to pass from said cup-shaped member into the pulp conduit below.

ALVA H. GARRETI. 

